mruby-io: rename mruby/ext/io.h to mruby/io.h

Simplify the header path to be consistent with mruby/time.h.
The ext/ subdirectory was unnecessary.

Co-authored-by: Claude <noreply@anthropic.com>

mrbgems/mruby-io/src/file.c

@@ -7,7 +7,7 @@
 #include <mruby/class.h>
 #include <mruby/data.h>
 #include <mruby/string.h>
-#include <mruby/ext/io.h>
+#include <mruby/io.h>
 #include <mruby/error.h>
 #include <mruby/presym.h>
 #include "io_hal.h"

mrbgems/mruby-io/src/file_test.c

@@ -6,7 +6,7 @@
 #include <mruby/class.h>
 #include <mruby/data.h>
 #include <mruby/string.h>
-#include <mruby/ext/io.h>
+#include <mruby/io.h>
 #include <mruby/error.h>
 #include <mruby/presym.h>
 #include <mruby/internal.h>

mrbgems/mruby-io/src/io.c

@@ -9,7 +9,7 @@
 #include <mruby/hash.h>
 #include <mruby/string.h>
 #include <mruby/variable.h>
-#include <mruby/ext/io.h>
+#include <mruby/io.h>
 #include <mruby/error.h>
 #include <mruby/internal.h>
 #include <mruby/presym.h>

mrbgems/mruby-io/test/mruby_io_test.c

@@ -65,7 +65,7 @@ mkdtemp(char *temp)
 #include <mruby/error.h>
 #include <mruby/string.h>
 #include <mruby/variable.h>
-#include <mruby/ext/io.h>
+#include <mruby/io.h>
 
 static mrb_value
 mrb_io_test_io_setup(mrb_state *mrb, mrb_value self)

mrbgems/mruby-socket/src/socket.c

@@ -38,7 +38,7 @@
 #include <mruby/internal.h>
 #include <mruby/presym.h>
 
-#include <mruby/ext/io.h>
+#include <mruby/io.h>
 #include "socket_hal.h"
 
 /* Address family information for compact lookup table */